Pyribenzoxim (Ref: LGC 40863 )	Last updated: 03/03/2021
(Also known as: pyanchor)

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SUMMARY

Pyribenzoxim is a post-emergence herbicide without EU regulatory approval for use. It has a low aqueous solubility and is volatile. Whilst data is sparse it indicates that the chemical is not persistent in soil systems. It has a low mammalian toxicity and is a recognised irritant. It is moderately toxic to birds, fish and honey bees.

GENERAL INFORMATION

Description	Used post-emergence to control grasses and polygonums in rice and other crops
Example pests controlled	Barnyard grass; Blackgrass; Knotweed
Example applications	Rice; Wheat
Efficacy & activity	-
Availability status	Unknown
Introduction & key dates	1997, Korea

UK regulatory status

UK COPR regulatory status	Not approved
Date COPR inclusion expires	Not applicable
UK LERAP status	No UK approval for use

EC Regulation 1107/2009 (repealing 91/414)

EC Regulation 1107/2009 status	Not approved
Dossier rapporteur/co-rapporteur	Not applicable
Date EC 1107/2009 inclusion expires	Not applicable
EU Candidate for substitution (CfS)	Not applicable
Listed in EU database	No
Approved for use (✓) under EC 1107/2009 in the following EU Member States	ATAustria BEBelgium BGBulgaria CYCyprus CZCzech Republic DEGermany DKDenmark EEEstonia ELGreece                   ESSpain FIFinland FRFrance HRCroatia HUHungary IEIreland ITItaly LTLithuania LULuxembourg                   LVLatvia MTMalta NLNetherlands PLPoland PTPortugal RORomania SESweden SISlovenia SKSlovakia

Also used in

Also used in	-

Chemical structure

Isomerism	-
Chemical formula	C₃₂H₂₇N₅O₈
Canonical SMILES	COC1=CC(=NC(=N1)OC2=C(C(=CC=C2)OC3=NC(=CC(=N3)OC)OC)C(=O)ON=C(C4=CC=CC=C4)C5=CC=CC=C5)OC
Isomeric SMILES	No data
International Chemical Identifier key (InChIKey)	OVXMBIVWNJDDSM-UHFFFAOYSA-N
International Chemical Identifier (InChI)	InChI=1S/C32H27N5O8/c1-39-24-18-25(40-2)34-31(33-24)43-22-16-11-17-23(44-32-35-26(41-3)19-27(36-32)42-4)28(22)30(38)45-37-29(20-12-7-5-8-13-20)21-14-9-6-10-15-21/h5-19H,1-4H3
2D structure diagram/image available?	Yes

General status

Pesticide type	Herbicide
Substance group	Unclassified
Minimum active substance purity	-
Known relevant impurities	-
Substance origin	Synthetic
Mode of action	Broad spectrum, inhibits plant amino acid synthesis - acetohydroxyacid synthase AHAS.
CAS RN	168088-61-7
EC number	-
CIPAC number	None allocated
US EPA chemical code	-
PubChem CID	178117
Molecular mass	609.59
PIN (Preferred Identification Name)	N-({2,6-bis[(4,6-dimethoxypyrimidin-2-yl)oxy]benzoyl}oxy)-1,1-diphenylmethanimine
IUPAC name	benzophenone O-[2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoyl]oxime
CAS name	diphenylmethanone O-(2,6-bis((4,6-dimethoxy-2-pyrimidinyl)oxy)benzoyl)oxime
Other status information	-
Relevant Environmental Water Quality Standards	-
Herbicide Resistance Classification (HRAC)	B
Herbicide Resistance Classification (WSSA)	2
Insecticide Resistance Classification (IRAC)	Not applicable
Fungicide Resistance Classification (FRAC)	Not applicable
Examples of recorded resistance	-
Physical state	White to pale yellow coloured solid

Formulations

Property	Value
Example manufacturers & suppliers of products using this active now or historically	Kiljabigold Pyanchor
Example products using this active	LG Chemicals, Korea
Formulation and application details	Usually supplied as an emulsifiable concentrate

ENVIRONMENTAL FATE

Property		Value	Source; quality score; and other information	Interpretation
Solubility - In water at 20 °C (mg l⁻¹)		3.5	R4 R = Peer reviewed scientific publications 4 = Verified data	Low
Solubility - In organic solvents at 20 °C (mg l⁻¹)		-	-	-
Melting point (°C)		129	R4 R = Peer reviewed scientific publications 4 = Verified data	-
Boiling point (°C)		811	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Degradation point (°C)		-	-	-
Flashpoint (°C)		444	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Octanol-water partition coefficient at pH 7, 20 °C	P	1.10 X 1003	Calculated	-
	Log P	3.04	R4 R = Peer reviewed scientific publications 4 = Verified data	High
Bulk density (g ml⁻¹)		1.3	E3 E = Manufacturers safety data sheets 3 = Unverified data of known source	-
Dissociation constant pKa) at 25 °C		-	-	-
		-
Vapour pressure at 20 °C (mPa)		0.99	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Low volatility
Henry's law constant at 25 °C (Pa m³ mol⁻¹)		-	-	-
Maximum UV-vis absorption L mol⁻¹ cm⁻¹		-	-	-
Surface tension (mN m⁻¹)		-	-	-

Degradation

Property		Value	Source; quality score; and other information	Interpretation
General biodegradability		-
Soil degradation (days) (aerobic)	DT₅₀ (typical)	-	-	-
	DT₅₀ (lab at 20 °C)	-	-	-
	DT₅₀ (field)	7	L3 L = Pesticide manuals and hard copy reference books / other sources 3 = Unverified data of known source	Non-persistent
	DT₉₀ (lab at 20 °C)	-	-	-
	DT₉₀ (field)	-	-	-
	DT₅₀ modelling endpoint	-	-	-
	Note	-
Dissipation rate RL₅₀ on plant matrix	Value	-	-	-
	Note	-
Dissipation rate RL₅₀ on and in plant matrix	Value	5.1	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source	-
	Note	Rice whole pant matrix, n=1
Aqueous photolysis DT₅₀ (days) at pH 7	Value	9.2	R4 R = Peer reviewed scientific publications 4 = Verified data (distilled water)	Moderately fast
	Note	-
Aqueous hydrolysis DT₅₀ (days) at 20 °C and pH 7	Value	26.9	R4 R = Peer reviewed scientific publications 4 = Verified data (de-aerated distilled water)	Non-persistent
	Note	-
Water-sediment DT₅₀ (days)		-	-	-
Water phase only DT₅₀ (days)		-	-	-

Soil adsorption and mobility

Property		Value	Source; quality score; and other information	Interpretation
Linear	Kd	-	-	-
	Koc	-
	Notes and range	-
Freundlich	Kf	9979	R4 R = Peer reviewed scientific publications 4 = Verified data	Non-mobile
	Kfoc	534500
	1/n	-
	Notes and range	Literature data: Kf range 2100 (clay) - 20654 (silt loam) mL g⁻¹, Kfoc values range 85700 (clay) - 2470000 (silt loam) mL g⁻¹
pH sensitivity		-

Fate indices

Property		Value	Source; quality score; and other information	Interpretation
GUS leaching potential index		-1.46	Calculated	Low leachability
SCI-GROW groundwater index (μg l⁻¹) for a 1 kg ha⁻¹ or 1 l ha⁻¹ application rate	Value	5.35 X 10-03	Calculated	-
	Note	Estimated concentrations of chemicals with Koc values greater than 9995 ml g⁻¹ are beyond the scope of the regression data used in SCI-GROW development. If there are concerns for such chemicals, a higher tier groundwater exposure assessment should be considered, regardless of the concentration returned by SCI-GROW
Potential for particle bound transport index		-	-	-
Potential for loss via drain flow		-	-	-

ECOTOXICOLOGY

Property		Value	Source; quality score; and other information	Interpretation
Bio-concentration factor	BCF (l kg⁻¹)	-	-	-
	CT₅₀ (days)	-		-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 5000	R4 R = Peer reviewed scientific publications 4 = Verified data Rat	Low
Mammals - Short term dietary NOEL	(mg kg⁻¹)	-	-	-
	(ppm diet)	-		-
Mammals - Chronic 21d NOAEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Birds - Acute LD₅₀ (mg kg⁻¹)		-	-	-
Birds - Short term dietary (LC₅₀/LD₅₀)		-	-	-
Birds - Chronic 21d NOEL (mg kg⁻¹ bw d⁻¹)		-	-	-
Fish - Acute 96 hour LC₅₀ (mg l⁻¹)		> 100	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source Orizias ¡atipes	Low
Fish - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic invertebrates - Acute 48 hour EC₅₀ (mg l⁻¹)		> 100	R4 R = Peer reviewed scientific publications 4 = Verified data Daphnia magna	Low
Aquatic invertebrates - Chronic 21 day NOEC (mg l⁻¹)		-	-	-
Aquatic crustaceans - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Acute 96 hour LC₅₀ (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, static, water (mg l⁻¹)		-	-	-
Sediment dwelling organisms - Chronic 28 day NOEC, sediment (mg kg⁻¹)		-	-	-
Aquatic plants - Acute 7 day EC₅₀, biomass (mg l⁻¹)		-	-	-
Non-target plants		-	-	-
		-	-	-
Algae - Acute 72 hour EC₅₀, growth (mg l⁻¹)		100	R3 R = Peer reviewed scientific publications 3 = Unverified data of known source Unknown species	Low
Algae - Chronic 96 hour NOEC, growth (mg l⁻¹)		-	-	-
Honeybees (Apis spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Unknown mode acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	> 100	L2 L = Pesticide manuals and hard copy reference books / other sources 2 = Unverified data of unknown source	Low
Bumblebees (Bombus spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
		-
Mason bees (Osmia spp.)	Contact acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
	Oral acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg bee⁻¹)	-	-	-
Other pollinators (1)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Other pollinators (2)	Acute LD₅₀ (worst case from 24, 48 and 72 hour values - μg insect⁻¹)	-	-	-
	Mode of exposure	-
Earthworms - Acute 14 day LC₅₀ (mg kg⁻¹)		-	-	-
Earthworms - Chronic NOEC, reproduction (mg kg⁻¹)		-	-	-
Other soil macro-organisms	Acute LC₅₀ (mg kg⁻¹)	-	-	-
	Chronic NOEC (mg kg⁻¹)	-	-	-
Other arthropod (1)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Other arthropod (2)	LR₅₀ g ha⁻¹	-	-	-
	% Effect	-	-	-
Soil micro-organisms		-	-	-
Mesocosm study data	NOEAEC mg l⁻¹	-	-	-
	NOEAEC mg l⁻¹	-	-	-

HUMAN HEALTH AND PROTECTION

General

Property		Value	Source; quality score; and other information	Interpretation
Threshold of Toxicological Concern (Cramer Class)		High (class III)	-	-
Mammals - Acute oral LD₅₀ (mg kg⁻¹)		> 5000	R4 R = Peer reviewed scientific publications 4 = Verified data Rat	Low
Mammals - Dermal LD₅₀ (mg kg⁻¹ body weight)		2000	R4 R = Peer reviewed scientific publications 4 = Verified data Rat	-
Mammals - Inhalation LC₅₀ (mg l⁻¹)		-	-	-
Other Mammal toxicity endpoints		-	-	-
ADI - Acceptable Daily Intake (mg kg⁻¹ bw day⁻¹)		-	-	-
ARfD - Acute Reference Dose (mg kg⁻¹ bw day⁻¹)		-	-	-
AAOEL - Acute Acceptable Operator Exposure Level (mg kg⁻¹ bw day⁻¹)		-	-	-
AOEL - Acceptable Operator Exposure Level - Systemic (mg kg⁻¹ bw day⁻¹)		-	-	-
Dermal penetration studies (%)		-	-	-
Dangerous Substances Directive 76/464		-	-	-
Exposure Routes	Public	-
	Occupational	-
MRLs	European	EU MRL pesticide database
	Notes	-
Drinking Water Standards		-	-	-
Drinking Water MAC (μg l⁻¹)		-	-	-

Health issues

Specific human health issues		Carcinogen Genotoxic Endocrine disruptor XNo, known not to cause a problem A0 A = Chromosome aberration (EFSA database) 0 = No data ; B0 B = DNA damage/repair (EFSA database) 0 = No data ; C0 C = Gene mutation (EFSA database) 0 = No data ; D0 D = Genome mutation (EFSA database) 0 = No data ; E0 E = Unspecified genotoxicity type (miscellaneous data source) 0 = No data No data found Reproduction / development effects Acetyl cholinesterase inhibitor Neurotoxicant No data found XNo, known not to cause a problem No data found Respiratory tract irritant Skin irritant Skin sensitiser ✓Yes, known to cause a problem ✓Yes, known to cause a problem No data found Eye irritant Phototoxicant   ✓Yes, known to cause a problem No data found
General human health issues		Harmful via inhalation, ingestion and in contact with skin

Handling issues

Property	Value and interpretation
General	No information available
CLP classification 2013	-
EC Risk Classification	Xn - Harmful: R20/21/22 Xi - Irritant: R36/37/38
EC Safety Classification	S26, S36, S37/39
WHO Classification	NL (Not listed)
UN Number	-
Waste disposal & packaging	-

TRANSLATIONS

Language	Name
English	pyribenzoxim
French	-
German	-
Danish	-
Italian	-
Spanish	-
Greek	-
Polish	pirybenzoksym
Swedish	-
Hungarian	-
Dutch	-

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Record last updated:	03/03/2021
Contact:	aeru@herts.ac.uk
Please cite as:	Lewis, K.A., Tzilivakis, J., Warner, D. and Green, A. (2016) An international database for pesticide risk assessments and management. Human and Ecological Risk Assessment: An International Journal, 22(4), 1050-1064. DOI: 10.1080/10807039.2015.1133242